High-pressure pumps pressurize water or other fluids to generate high-pressure fluid streams that may be used to cut materials (e.g., sheet metal and fiber-cement siding), drive actuators and other applications where high-pressure fluids are useful. A typical high-pressure pump has a pressurization chamber, a plunger within the pressurization chamber, an inlet check valve coupled to the pressurization chamber, and an outlet check valve coupled to between the pressurization chamber and an outlet chamber. The plunger reciprocates within the pressurization chamber drawing fluid into the pressurization chamber via the inlet check valve on an intake stroke and driving the fluid through the outlet check valve into the outlet chamber on a pressurizing stroke. The outlet check valve selectively allows fluid at a sufficient pressure to enter the outlet chamber. High-pressure pumps generally operate above 10,000 psi, and in many applications in a range of 50,000 psi-100,000 psi or above.
Because high-pressure pumps operate at such high-pressures, the pumps are subject to fluid leaks that may impair the performance of the pumps or cause failure. One conventional technique to monitor whether a pump is leaking is to manually touch the pump head to estimate whether the operating temperature of the pump is above normal operating temperatures. Another conventional technique for monitoring pumps is to measure the temperature of the pressurized fluid downstream from the pump head. However, as set forth below, conventional techniques for monitoring the status of high-pressure pumps are beset with several deficiencies.
One problem with the conventional monitoring techniques is that a pump may fail without any warning. In manual monitoring applications, for example, a rise in the temperature of the pump head sufficient to sense by touch generally occurs only after a component has completely failed causing a rupture or significant loss in pressure. Similarly, it is difficult to determine that a pump head is malfunctioning by measuring the temperature downstream from the pump head because many factors influence the temperature of the pressurized fluid in the pump head. Thus, large leaks may not be detected until they rupture or cause other catastrophic failures under the high-pressure operating conditions.
Another problem with conventional monitoring techniques is that they do not identify the specific component that is malfunctioning. The conventional techniques merely provide a general indication that a component in the pump head has failed. Accordingly, to repair a failed pump, the pump head is disassembled and each of the inlet check valve, the outlet check valve or the plunger seal around the plunger is checked to determine the faulty component. It will be appreciated that checking each of these components increases the labor costs and the down-time associated with repairing pumps. Conventional monitoring techniques, therefore, may not provide adequate information to cost effectively operate and repair high-pressure pump heads.